用PHP模拟登陆_PHP

<?php
/*
* 得到网页内容
* 参数：$host [in] string
* 主机名称（例如： http://www.imsorry.com.cn）
* 参数：$method [in] string
* 提交方法：POST, GET, HEAD … 并加上相应的参数( 具体语法参见 RFC1945，RFC2068 )
* 参数：$str [in] string
* 提交的内容
* 参数：$sessid [in] string
* PHP的SESSIONID
*
* @返回 网页内容 string
*/
function GetWebContent($host, $method, $str, $sessid = ”)
{
$ip = gethostbyname($host);
$fp = fsockopen($ip, 80);
if (!$fp) return;
fputs($fp, “$method\r\n”);
fputs($fp, “Host: $host\r\n”);
if (!empty($sessid))
{
fputs($fp, “Cookie: PHPSESSID=$sessid; path=/;\r\n”);
}
if ( substr(trim($method),0, 4) == “POST”)
{
fputs($fp, “Content-Length: “. strlen($str) . “\r\n”); // 别忘了指定长度
}
fputs($fp, “Content-Type: application/x-www-form-urlencoded\r\n\r\n”);
if ( substr(trim($method),0, 4) == “POST”)
{
fputs($fp, $str.”\r\n”);
}
while(!feof($fp))
{
$response .= fgets($fp, 1024);
}
$hlen = strpos($response,”\r\n\r\n”); // LINUX下是 “\n\n”
$header = substr($response, 0, $hlen);
$entity = substr($response, $hlen 4);
if ( preg_match(‘/PHPSESSID=([0-9a-z] );/i’, $header, $matches))
{
$a[‘sessid’] = $matches[1];
}
if ( preg_match(‘/Location: ([0-9a-z\_\?\=\&\#\.] )/i’, $header, $matches))
{
$a[‘location’] = $matches[1];
}
$a[‘content’] = $entity;
fclose($fp);
return $a;
}

/* 构造用户名，密码字符串 */
$str = (“username=test&password=test”);
$response = GetWebContent(“localhost”,”POST /login.php HTTP/1.0″, $str);
echo $response[‘location’].$response[‘content’].”
“;
echo $response[‘sessid’].”
“;
if ( preg_match(‘/error\.php/i’,$response[‘location’]))
{
echo “登陆失败
“;
} else {
echo “登陆成功
“;
// 不可以访问user.php，因为不带sessid参数
$response = GetWebContent(“localhost”,”GET /user.php HTTP/1.0″, ”, ”);
echo $response[‘location’].”
“; // 结果：error.php?errcode=2

// 可以访问user.php
$response = GetWebContent(“localhost”,”GET /user.php HTTP/1.0″, ”, $response[‘sessid’]);
echo $response[‘location’].”
“; // 结果：user.php
}
?>